[pymvpa] Accounting for the haemodynamic lag

[J.A. Etzel]

> But if I ever wanted to do an event-related design where
> measuring timings precisely is more important then I'm not sure if simply
> offsetting the timeseries would still be considered acceptable.

Simple offsetting is generally "considered acceptable", even for 
event-related designs. Is is "considered optimal"? No. But it might have 
less of a risk of introducing artifacts or distorting signal than using 
a poorly-fitting (or too-complex) model.

Another relevant reference is Akama et al 2012 
(DOI:10.3389/fninf.2012.00024): figure 4 compares the canonical HRF and 
single-volume classification accuracies. They're close, but not 
identical, another example of how the information in fMRI is really 
blurred over time.

Jo


-- 
Joset A. Etzel, Ph.D.
Research Analyst
Cognitive Control & Psychopathology Lab
Washington University in St. Louis
http://mvpa.blogspot.com/